Apparatus and Method for Manufacturing A Composite Golf Club Head

ABSTRACT

A method and apparatus for manufacturing a preform component for a golf club head composed of a plurality of plies of pre-preg material is disclosed herein. The preform component is preferably a face component, a crown component or a sole component, composed of a plurality of plies of pre-preg material. The apparatus preferably has a plunger head attached to a pneumatic cylinder for compressing the plies of pre-preg sheets within a mold cavity configured to define a preform component.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a divisional application of U.S. patentapplication Ser. No. 09/683,665, which is a continuation-in-partapplication of U.S. patent application Ser. No. 09/877,652, filed onJun. 8, 2001, now U.S. Pat. No. 6,440,008, which is a continuation ofU.S. patent application Ser. No. 09/474,670, filed on Dec. 29, 1999, nowU.S. Pat. No. 6,248,025, which is continuation-in-part application ofU.S. patent application Ser. No. 08/958,723, filed on Oct. 23, 1997, nowU.S. Pat. No. 6,010,411.

FEDERAL RESEARCH STATEMENT

[0002] Not Applicable

BACKGROUND OF INVENTION

[0003] 1. Field of the Invention

[0004] The present invention relates to a manufacturing method for agolf club head composed of plies of pre-preg sheets. More specifically,the present invention relates to a bladder-mold manufacturing method fora golf club head composed of plies of pre-preg sheets.

[0005] 2. Description of the Related Art

[0006] One of the first (if not the first) disclosures of a golf clubhead composed of a plurality of plies of a pre-preg material is GreatBritain Patent Application Number 1201648 which was filed in 1967 onbehalf of William Charles Carlton.

[0007] In 1984, U.S. Pat. No. 4,449,707 issued to Hayashi et al., for aGolf Club Head Of Carbon Fiber Reinforced Plastic, based on a JapanesePatent Application originally filed in 1982. The Hayashi patentdiscloses surrounding a core with a fiber reinforced fabric to create agolf club head with a proper center of gravity.

[0008] Another disclosure is U.S. Pat. No. 4,545,580 to Tomita et al.,for a Wood-Type Golf Club Head, based on a Japanese Patent Applicationoriginally filed in 1983. The Tomita patent discloses a durable golfclub head having an outer shell composed of a fiber reinforced plasticmaterial, a foam center core, and an intermediate shell formed of athermoplastic resin material.

[0009] Yet another disclosure is U.S. Pat. No. 4,630,826 to Nishigaki etal., for Golf Club Head. The Nishigaki patent discloses body composed ofa carbon resin layer and a cast resin layer with a face insert blockcomposed of a ceramic material.

[0010] Still another disclosure is U.S. Pat. No. 4,778,185 to Kurokawa,for Wood-Type Core-Shell Golf Club Heads, based on a Japanese PatentApplication originally filed in 1984. The Kurokawa patent discloses agolf club head composed of a foam core and a shell composed of amaterial fiber reinforced plastic having long and short fibers.

[0011] Yet another disclosure is U.S. Pat. No. 4,793,616 to Fernandez,for Golf Club. The Fernandez patent discloses a club head shell composedresin impregnated fibers and ceramic particles within the resin toprovide a high strength shell.

[0012] Yet another disclosure is U.S. Pat. No. 5,154,425 to Niskanen etal., for a Composite Golf Club Head. The Niskanen patent discloses aclub head composed of a metal matrix composite of a ceramic matrixcomposite.

[0013] When a golf club head strikes a golf ball, large impacts areproduced that load the club head face and the golf ball. Most of theenergy is transferred from the head to the golf ball, however, someenergy is lost as a result of the collision. The golf ball is typicallycomposed of polymer cover materials (such as ionomers) surrounding arubber-like core. These softer polymer materials having damping (loss)properties that are strain and strain rate dependent which are on theorder of 10-100 times larger than the damping properties of a metallicclub striking plate. Thus, during impact most of the energy is lost as aresult of the high stresses and deformations of the golf ball (0.001 to0.20 inches), as opposed to the small deformations of the metallic clubface (0.025 to 0.050 inches). A more efficient energy transfer from theclub head to the golf ball could lead to greater flight distances of thegolf ball.

[0014] The generally accepted approach has been to increase thestiffness of the club head face to reduce metal or club headdeformations. However, this leads to greater deformations in the golfball, and thus increases in the energy transfer problem.

[0015] Some have recognized the problem and disclosed possiblesolutions. An example is Campau, U.S. Pat. No. 4,398,965, for a MethodOf Making Iron Golf Clubs With Flexible Impact Surface, which disclosesa club having a flexible and resilient face plate with a slot to allowfor the flexing of the face plate. The face plate of Campau is composedof a ferrous material, such as stainless steel, and has a thickness inthe range of 0.1 inches to 0.125 inches.

[0016] Another example is Eggiman, U.S. Pat. No. 5,863,261, for a GolfClub Head With Elastically Deforming Face And Back Plates, whichdiscloses the use of a plurality of plates that act in concert to createa spring-like effect on a golf ball during impact. A fluid is disposedbetween at least two of the plates to act as a viscous coupler.

[0017] Yet another example is Jepson et al, U.S. Pat. No. 3,937,474, fora Golf Club With A Polyurethane Insert. Jepson discloses that thepolyurethane insert has a hardness between 40 and 75 shore D.

[0018] Still another example is Inamori, U.S. Pat. No. 3,975,023, for aGolf Club Head With Ceramic Face Plate, which discloses using a faceplate composed of a ceramic material having a high energy transfercoefficient, although ceramics are usually harder materials. Chen etal., U.S. Pat. No. 5,743,813 for a Golf Club Head, discloses usingmultiple layers in the face to absorb the shock of the golf ball. One ofthe materials is a non-metal material.

[0019] Lu, U.S. Pat. No. 5,499,814, for a Hollow Club Head WithDeflecting Insert Face Plate, discloses a reinforcing element composedof a plastic or aluminum alloy that allows for minor deflecting of theface plate which has a thickness ranging from 0.01 to 0.30 inches for avariety of materials including stainless steel, titanium, KEVLAR®, andthe like. Yet another Campau invention, U.S. Pat. No. 3,989,248, for aGolf Club Having Insert Capable Of Elastic Flexing, discloses a woodclub composed of wood with a metal insert.

[0020] The Rules of Golf, established and interpreted by the UnitedStates Golf Association (“USGA”) and The Royal and Ancient Golf Club ofSaint Andrews, set forth certain requirements for a golf club head. Therequirements for a golf club head are found in Rule 4 and Appendix II. Acomplete description of the Rules of Golf are available on the USGA webpage at www.usga.org. Although the Rules of Golf do not expressly statespecific parameters for a golf club face, Rule 4-1e prohibits the facefrom having the effect at impact of a spring with a golf ball. In 1998,the USGA adopted a test procedure pursuant to Rule 4-1e which measuresclub face COR. This USGA test procedure, as well as procedures like it,may be used to measure club face COR.

[0021] Although the prior art has disclosed many club head composed ofcomposite materials, the prior art has failed to provide a golf clubhead composed of a composite material that is lightweight, forgiving andhas a high coefficient of restitution.

SUMMARY OF INVENTION

[0022] The present invention provides a method for manufacturing a golfclub head that is composed of a composite material and is forgivingwhile providing better performance than other composite golf club heads.

[0023] One aspect of the present invention is a method for producing agolf club head composed of plies of pre-preg sheets. The method beginsby creating a face component composed of plies of pre-preg sheets. Acrown component composed of plies of pre-preg sheets is created next andthen a sole component composed of plies of pre-preg sheets is createdusing the method. The face, crown and sole components are then assembledto create an assembled unit with an inflatable bladder located within ahollow interior of the assembled unit. The assembled unit is thenpre-compacted to create a pre-compacted unit. Finally, the pre-compactedunit is bladder molded to create a molded golf club head.

[0024] Having briefly described the present invention, the above andfurther objects, features and advantages thereof will be recognized bythose skilled in the pertinent art from the following detaileddescription of the invention when taken in conjunction with theaccompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0025]FIG. 1 is an exploded view of a golf club head manufactured by themethod of the present invention.

[0026]FIG. 2 is a front view of a golf club head manufactured by themethod of the present invention.

[0027]FIG. 2A is a front view of a golf club head manufactured by themethod of the present invention.

[0028]FIG. 3 is a top plan view of a golf club head manufactured by themethod of the present invention.

[0029]FIG. 4 is a heel end view of a golf club head manufactured by themethod of the present invention.

[0030]FIG. 5 is a toe end view of a golf club head manufactured by themethod of the present invention.

[0031]FIG. 6 is a bottom plan view of a golf club head manufactured bythe method of the present invention.

[0032]FIG. 7 is a cross-sectional view of the golf club head of FIG. 3along line 7-7.

[0033]FIG. 8 is a cross-sectional view of the golf club head of FIG. 2along line 8-8.

[0034]FIG. 9 is an isolated cross-section view of a face preform of thepresent invention.

[0035]FIG. 9A is an enlarged view of area 9A of FIG. 9.

[0036]FIG. 9B is an enlarged view of area 9B of FIG. 9.

[0037]FIG. 10 is an isolated cross-section view of a crown/face preformof a golf club head of the present invention.

[0038]FIG. 11 is an isolated cross-section view of a sole preform of thepresent invention.

[0039]FIG. 12 is a top plan view of a golf club head manufactured by themethod of the present invention illustrating the variation in thicknessof the walls of the golf club head.

[0040]FIG. 13 is a front plan view of a golf club head manufactured bythe method of the present invention illustrating the variation inthickness of the walls of the golf club head.

[0041]FIG. 14 is a bottom plan view of a golf club head manufactured bythe method of the present invention illustrating the variation inthickness of the walls of the golf club head.

[0042]FIG. 15 is a heel end view of a golf club head manufactured by themethod of the present invention illustrating the variation in thicknessof the walls of the golf club head.

[0043]FIG. 16 is a plan view of a face/crown ply having a ninety degreeorientation.

[0044]FIG. 17 is a plan view of a full face ply having a ninety degreeorientation.

[0045]FIG. 18 is a plan view of a face doubler ply having a ninetydegree orientation.

[0046]FIG. 19 is a plan view of a sole ply having a negative forty-fivedegree orientation.

[0047]FIG. 20 is a flow chart of the general method of the presentinvention.

[0048]FIG. 21 is a flow chart of the face component creation step of themethod of the present invention.

[0049]FIG. 22 is a flow chart of the compressing molding step of themethod of the present invention.

[0050]FIG. 23 is a perspective view of the preform manufacturingapparatus.

[0051]FIG. 24 is a left side view of the preform apparatus.

[0052]FIG. 25 is a right side view of the preform apparatus.

[0053]FIG. 26 is a bottom plan view of the preform apparatus.

[0054] FIGS. 27A-B are schematic views of the plunger head for the facecomponent.

[0055] FIGS. 28A-B are schematic views of the plunger head for the solecomponent.

[0056] FIGS. 29A-B are schematic views of the plunger head for the crowncomponent.

DETAILED DESCRIPTION

[0057] The present invention is directed at an apparatus and method formanufacturing a preform component composed of plies of pre-preg sheetsfor a golf club head. The preform component is a crown component, a solecomponent, and/or a face component. The golf club head is preferablycomposed of a plurality of plies of pre-preg sheets. Alternatively,portions of the golf club head are composed of metals or injected moldedpolymers.

[0058] As shown in FIGS. 1-6, a golf club head is generally designated20. The club head 20 is either a fairway wood or a driver. The driversrange in loft angle of from six degrees to fifteen degrees. The clubhead 20 has a body 22 that is generally composed of a composite materialsuch as plies of carbon pre-preg sheets, however, portions may becomposed of metal or injected molded polymers. The body 22 has a crown24, a striking plate 26, a sole 28 with a bottom portion 28 a and aribbon 30. The ribbon preferably has an upper ribbon wall 30 a and alower ribbon wall 30 b. The ribbon 30 generally extends from a toe end32 to a heel end 34. The ribbon 30 generally begins at one end of thestriking plate 26 and ends at an opposite end of the striking plate 26.A rear 36 of the body 22 is opposite the striking plate 26 and isdefined by portions of the ribbon 30, the crown 24 and the sole 28.Also, at the heel end 34 of the club head 20 is an internal tube 38 withan opening 39 for placement of a shaft therein. The internal tube 38 isplaced within the hollow interior 44 of the body 22. A weight member 40is preferably located within the ribbon 30.

[0059] A sole plate 42 is disposed within a recess 29 of the bottomportion 28 a of the sole 28. The sole plate 42 is preferably composed ofa metal material such as aluminum or titanium, and preferably has a massof 5 grams to 20 grams. A preferred mass for an aluminum sole plate 42is approximately 11 grams, and a preferred mass for a titanium soleplate 42 is approximately 18 grams. The sole plate 42 is preferablybonded within the recess 29 through the use of adhesives. The sole plate42 preferably has embossed graphics thereon. The sole plate 42 increasesthe durability of the club head 20 since the sole 28 often impacts theground during the striking of a golf ball.

[0060] The club head 20 also has a greater volume than a composite clubhead of the prior art while maintaining a weight that is substantiallylower or equivalent to that of the prior art. The volume of the clubhead 20 ranges from 175 cubic centimeters to 450 cubic centimeters, morepreferably ranges from 300 cubic centimeters to 400 cubic centimeters,and is most preferably 360 cubic centimeters for a driver. The mass ofthe club head 20 ranges from 165 grams to 300 grams, preferably rangesfrom 175 grams to 225 grams, and most preferably from 188 grams to 195grams. The body 22 of plies of pre-preg material has a mass ranging from80 grams to 120 grams, and most preferably 98 grams.

[0061] The volume of the golf club head 20 is increased by increasingthe vertical distance of the club head 20 from the sole 28 to the crown24, as opposed to the horizontal distance of the heel end 34 to the toeend 32. This increase in volume is brought about by the dual wallstructure of the ribbon 30. The upper ribbon wall 30 a is approximatelyperpendicular relative to the crown 24, while the lower ribbon wall 30 bpreferably has an angle between 25 degrees and 75 degrees relative tothe crown 24. The greater volume of the club head 20 allows the clubhead 20 to be more forgiving than prior art golf club heads whileproviding better performance. The mass of club head 20 is much lowerthan metal club heads of similar volumes, and thus the large volume doesnot deter from the swing of a golfer.

[0062] The striking plate 26 has a smaller aspect ratio than strikingplates of the prior art. The aspect ratio as used herein is defined asthe width, “w”, of the striking plate divided by the height, “h”, of thestriking plate 26, as shown in FIG. 2A. In one embodiment, the width wis 90 millimeters and the height h is 54 millimeters giving an aspectratio of 1.666. In conventional golf club heads, the aspect ratio isusually much greater than 1. For example, the original GREAT BIG BERTHA®driver had an aspect ratio of 1.9. The aspect ratio of the presentinvention preferably ranges from 1.0 to 1.7.

[0063] As shown in FIG. 7, the internal tube 38 lies within the hollowinterior 44 of the club head 20. The internal tube is preferablycomposed of a metal material and has a mass ranging from 8 grams to 20grams. The internal tube 38 is most preferably composed of stainlesssteel and has a mass of approximately 14 grams. The internal tubing 38has a bore 130 to receive an insert and a shaft, not shown, therein.Such an insert is discussed in U.S. Pat. No. 6,352,482, for a Golf ClubWith Hosel Liner, which is hereby incorporated by reference in itsentirety. Preferably, the club head 20 has a hollow interior 44 definedby the body 22, however, the light weight of the composite body 22allows for numerous manipulations in placement of weight, foam, soundenhancing devices and the like within the hollow interior 44.

[0064] Referring specifically to FIG. 1, the club head 20 has a weightmember 40 disposed within the plies of pre-preg that compose the ribbon30 of the club head 20. Preferably, the weight member 40 is composed ofthree weight members 40 a, 40 b and 40 c. One such weight member 40 isdescribed in U.S. Pat. No. 6,386,990, filed on Dec. 29, 1999, andentitled A Composite Golf Club Head With An Integral Weight Strip, whichis hereby incorporated by reference in its entirety. The weight member40 is preferably composed of a polymer material integrated with a metalmaterial. The metal material is preferably selected from copper,tungsten, steel, aluminum, tin, silver, gold, platinum, or the like. Apreferred metal is tungsten. The weight member 40 has a density greaterthan the composite material of the body 22. Preferably, the weightmember 40 extends from approximately the heel end 34 of the strikingplate 26 through the rear 36 to the toe end 32 of the striking plate 26.However, the weight member 40 may only extend along the rear 36 of theribbon 30, the heel end 34 of the ribbon 30, the toe end 32 of theribbon 30, or any combination thereof. Those skilled in the pertinentart will recognize that other weighting materials may be utilizedwithout departing from the scope and spirit of the present invention.

[0065] The placement of the weighting members 40 a-c allows for themoment of inertia of the golf club head 20 to be optimized. A morethorough description of the optimization of the moments of inertia isdisclosed in U.S. Pat. No. 6,607,452, entitled High Moment of InertiaComposite Golf Club, and hereby incorporated by reference in itsentirety. In one preferred example of the golf club head 20 of thepresent invention, the moment of inertia about the Ixx axis through thecenter of gravity is approximately 2566 grams-centimeters squared(“g-cm²”), the moment of inertia about the Iyy axis through the centerof gravity is approximately 1895 g-cm², and the moment of inertia aboutthe Izz axis through the center of gravity is approximately 3368 g-cm².

[0066] As shown in FIGS. 8, 9, 9A and 9B, a return portion 100 is atransition area from a perimeter 29 of the striking plate 26 rearwardtowards the crown 24. The return portion 100 has a thickness rangingfrom 0.100 inch to 0.200 inch to control the compliance of the strikingplate 26. The return portion 100 has an upper section 100 a, a lowersection 100 b, a heel section 100 c, not shown, and a toe section 100 d,not shown. The return portion 100 also has a taper region 101, whichincludes an upper tapering region 101 a, a lower tapering region 101 b,a heel tapering region 10 c, not shown, and a toe tapering region 101 d,not shown. The tapering region 101 tapers in thickness from a greaterthickness nearer the striking plate portion 26 to a lesser thicknessrearward toward the crown 24.

[0067] The return portion 100 has a predetermined length, which extendsrearward from the perimeter 29 of the striking plate portion 26 into thecrown 24. Preferably, the distance of the return portion 100, “Dr”,ranges from 0.25 inch to 2.0 inches, more preferably from 0.5 inch to1.75 inches, and most preferably 1.5 inches. Preferably, the distancefrom the perimeter 29 to the beginning of the tapering region 101 of thereturn portion 100 ranges from 0.25 inch to 1.5 inches, and mostpreferably 1.0 inch.

[0068] The body 22 is manufactured from a face component 125, whichincludes the striking plate portion 26 and the return portion 100, acrown component 124 and a sole component 128. The crown component 124overlaps the face component 125, as shown in FIG. 10. The sole component128 includes the ribbon portion 30 and the bottom portion 28 a. The solecomponent 128 is attached to the crown component 124 and the facecomponent 125.

[0069] FIGS. 16-19 illustrate preferred pre-preg sheets for forming thecomposite body of the golf club head 20. FIG. 16 illustrates aface/crown ply pre-preg sheet that is generally designated 55. Theface/crown ply 55 has a plurality of fibers 51 dispersed within a resinbody 53. The fibers 51 are preferably composed of a carbon material.Alternatively, the fibers 51 may be aramid fibers, glass fibers or thelike. The resin is typically an epoxy material. The relation of thefibers 51 to the striking plate 26, when the striking plate 26 is in aposition to strike a golf ball, determines the orientation of the fibers51. If the fibers 51 are parallel with the ground, or in other wordsextending across from the toe end to the heel end, then the face/crownply 55 has a zero degree orientation. If the fibers 51 are approximatelyperpendicular to the ground, as shown in FIG. 16, or in other wordsextending from the crown to the sole, then the face/crown ply 55 has aninety degrees orientation.

[0070]FIG. 17 illustrates a full face ply pre-preg sheet that isgenerally designated 57. As with the face/crown ply 55, the full faceply 57 has a plurality of fibers 51 dispersed within a resin body 53.The fibers 51 extend from the sole 28 to the crown 24, and thus the fullface ply 57 has fibers 51 that are perpendicular to the ground when itis in a position for striking a golf ball. Therefore, the full face ply57 of FIG. 17 has a ninety degrees orientation.

[0071]FIG. 18 illustrates a face doubler ply pre-preg sheet that isgenerally designated 58. As with the face/crown ply 55, the face doublerply 58 has a plurality of fibers 51 dispersed within a resin body 53.The fibers 51 extend from the sole 28 to the crown 24, and thus the facedoubler ply 58 has fibers 51 that are perpendicular to the ground whenit is in a position for striking a golf ball. Therefore, the facedoubler ply 58 of FIG. 18 has a ninety degrees orientation.

[0072]FIG. 19 illustrates a sole ply pre-preg sheet that is generallydesignated 59. As with the face/crown ply 55, the sole ply 59 has aplurality of fibers 51 dispersed within a resin body 53. The fibers 51extend at a forty-five degree angle relative to the ground when it is ina position for striking a golf ball. Therefore, the sole ply 59 of FIG.19 has a forty-five degree orientation.

[0073] As previously stated, the preferred composite material is pliesof carbon pre-peg sheets. Plies of pre-preg composite sheets aremanufacby pulling strands of fiber in a parallel motion, preferablycarbon, aramid or glass fiber, through a resin film and allowing theresin to partially cure or “stage”. When the resin is partially staged,the resin holds the fibers together such that the fibers form amalleable sheet with all of the fibers in a specific orientationrelative to an edge of the sheet. Preferred orientations are zerodegrees, plus forty-five degrees, minus forty-five degrees and ninetydegrees. Exemplary carbon pre-preg fiber sheets may be obtained fromNewport Composites of Santa Ana, Calif., Fiberite Inc. of GreenTexas, orHexcel Inc. of Pleasonton, Calif.

[0074] The manipulation of the thickness of the various regions of thebody 22 allows the golf club head 20 to have superior durability,forgiveness and performance as compared to prior art composite golf clubheads. As shown in FIGS. 12-15, the thickness of the body 22 is focusedon the striking plate portion 26. In a most preferred example: theregion designated A of the striking plate portion 26 has a thickness ofapproximately 0.169 inch; the region designated B, at the junction ofthe crown 24 and striking plate 26 has a thickness of approximately0.188 inch; the region designated C of the bottom portion 28 a of thesole 28 has a thickness of approximately 0.221 inch; the regiondesignated D of the ribbon 30 and of the bottom portion 28 a has athickness of approximately 0.202 inch; the region designated E of thecrown 24, the bottom portion 28 a and the ribbon 30 has a thickness ofapproximately 0.033 inch; and the region designated F of the crown 24has a thickness of approximately 0.191 inch. The regions designated Z1,Z2, Z3, Z4, Z5 and Z6 are tapering zones where the thickness tapersrearward.

[0075] The golf club head 20 is preferably manufactured using a bladdermolding process. One such process is described in U.S. Pat. No.6,248,025, which is hereby incorporated by reference.

[0076]FIG. 20 illustrates the general method of the present invention.At block 200, the face component 125 or face cup preform is created bylaying up a plurality of plies of pre-preg sheets. The plies of pre-pregsheets create the striking plate 26 and the return portion 100 of theface component 125. A detailed example of the face component 125 is setforth below. At block 202, the crown component 124 or crown preform iscreated by laying up a plurality of plies of pre-preg sheets over theface component 125 as shown in FIG. 10. The plies of pre-preg sheetscreate the crown 24, the striking plate 26 and the return portion 100. Adetailed example of the crown component 124 is set forth below. At block204, the sole component 128 or sole preform is created by laying up aplurality of plies of pre-preg sheets with a plurality of weight members40 a-c. The plies of pre-preg sheets are folded over the plurality ofweight members 40 a-c. The plies of pre-preg sheets create the ribbon 30and the bottom portion 28 a. A detailed example of the sole component128 is set forth below.

[0077] At block 206, the face cup component 125, crown component 124 andsole component 128 are assembled to form an assembled unit. Aninflatable bladder, preferably made from latex, silicone, or similarmaterials, is placed within the interior of the assembled unit duringassembly and an access end of the bladder is placed through the bladderport. At block 208, the assembled unit is placed within a compactiondevice and pre-compacted to form a pre-compacted unit. At block 210, thepre-compacted unit is placed within a compression mold for bladdermolding of the pre-compacted unit into a molded unfinished golf clubhead. At block 212, the molded golf club head is finished to create thegolf club head 20.

[0078] During the bladder molding, a source of pressurized gas (notshown) is attached by a gas line to the bladder, and the bladder isinflated within the hollow interior of the pre-compacted unit. Thebladder engages the inside surface of the pre-compacted unit, forcingthe plies of pre-preg sheets against the inner wall of the compressionmold. The mold is then heated at a predetermined temperature for aselected period of time, i.e., a time sufficient to allow proper curingof the resin within the pre-preg sheets. After depressurizing, thebladder is removed through the bladder port 43, and the moldedunfinished golf club head is removed from the compression mold. Thoseskilled in the art will appreciate that, depending upon the type ofresin used, curing temperatures may range from 250° to 800° F., therequisite curing time may range from a few minutes (for example, in thecase of a “quick cure” epoxy or a thermoplastic resin) to 1.5 hours, andthe pressure applied via the latex or silicone bladder may range from100 to 300 psi.

[0079]FIG. 21 illustrates the face component creation process of block200 of FIG. 20. At block 300, a first predetermined quantity of plies ofpre-preg sheets for the face component 125 are placed within a cavityconfigured to approximate the face component 125. At block 302, thisfirst predetermined quantity of plies of pre-preg sheets for the facecomponent 125 are compressed by using a plunger or other similar deviceto create a stack of compressed plies. At block 304, a secondpredetermined quantity of plies of pre-preg sheets for the facecomponent 125 are placed within the cavity over the compressed plies. Atblock 306, this second predetermined quantity of plies of pre-pregsheets for the face component 125 are compressed by using a plunger orother similar device to create a stack of more compressed plies. Atblock 308, the process is repeated until a desired thickness of the facecomponent 125 is achieved by the process.

[0080] This process may be repeated to form both the crown component andthe sole component. It would be necessary prior to repeating the stepsto exchange the mold cavities so that the appropriate mold cavity isconfigured to approximate the crown component 124 in forming the crownpreform, or to approximate the sole component 128 in forming the solepreform.

[0081]FIG. 22 is a flow chart of the assembly and pre-compaction steps.At block 400, the face-component/crown component is created by laying upthe plies of the crown component over the face component 125. At block402, the inflatable bladder is placed within the sole component 128 andextended through the bladder port 43. At block 404, the assembled unitis placed within a compaction mold, and an extension of the bladder isextended through a bore in the mold. At block 406, the compaction moldis sealed and the assembled unit is compacted to form the pre-compactionunit.

[0082] In a preferred embodiment, the face component 125 is composed offorty-eight plies of pre preg sheets: forty full face plies 57 inorientations of zero degrees, plus forty-five degrees, minus forty-fivedegrees and ninety degrees; and eight face doubler plies 58 in zerodegrees and ninety degrees orientations. The crown component 124, whichis applied over the face component 125, is composed of seven face/crownplies 55 in orientations of zero degrees, plus forty-five degrees, minusforty-five degrees and ninety degrees. The sole component 128 iscomposed of seven sole plies 59 in orientations of zero degrees, plusforty-five degrees, minus forty-five degrees and ninety degrees. Thesecond and third pairs of sole plies 59 are folded over the plurality ofweight members 40 a-c. In a preferred embodiment, the outer plies are atwill pattern for aesthetic purposes and some durability support.

[0083] FIGS. 23-26 illustrate an apparatus 130 used in forming thepreforms for a golf club head. The apparatus 130 comprises a mold 132having an opening 133 in the top portion to define a cavity 134. Themold 132 is mounted to the apparatus 130 by a mold support plate 136.The mold support plate 136 is attached to the mold 132 at a top locationand to a mold base plate 138 at a bottom location. The mold base plate138 is held in place by attachment to a base 140 of the apparatus 130.The base 140 of the apparatus 130 may be free standing or may be mountedto a support structure using tabs 141 or other means of attachment.

[0084] The mold cavity 134 may be configured to approximate a face cupcomponent 125, crown component 124 or sole component 128 by having aninterior surface that conforms to the shape and volume of the componentto be molded. A plunger head 142 is mounted on a removable plunger plate144. The plunger head 142 is comprised of silicone, urethane or otherelastomeric materials and preferably has a durometer ranging from 25 to85 shore A and an elongation range of 100% to 700%. The plunger head 142and removable plunger plate 144 is located above the cavity 134 and isused to compress the plies of pre-preg sheets into the cavity 134. Theplunger head 142 may be of various sizes to approximate the size of thecavity 134 and is designed so that as the size of the plunger head 142decreases, the corresponding volume of the preform that is created byusing the plunger head 142 decreases. The removable plunger plate 144allows for an assortment of plunger heads 142 to be interchanged toapproximate the particular cavity size chosen for manufacturing apreform of the face cup component 125, crown component 124 and solecomponent 128.

[0085] Once the particular preform to be manufactured is chosen, theplunger head 142 is activated to press the plies into the cavity to formthe preform. Preferable pressure ranges for the plunger head 142 mayrange from 30-80 psi, however these ranges may be increased or decreaseddepending upon variations in the materials chosen to fabricate thepreforms. The removable plunger plate 144 with attached plunger head 142is mounted to a fixed plate 146. The fixed plate 146 is subsequentlyattached via an attachment piece 148 to a moveable rod 150 located in abottom portion of a lower support plate 152. The lower support plate 152is used to support a pnuematic cylinder 154. Thus aligning the pnuematiccylinder 154, plunger head 142, and cavity 134 along a longitudinalaxis. The pnuematic cylinder 154 travels up and down in a verticaldirection to allow oscillation of the plunger head 142 in and out of thecavity 134 along this longitudinal axis. A release lever 156 is locatedon the mold support plate 136 and is used to raise the plunger head 142once the pre-preg plies have been compressed in the cavity 134. Thepnuematic cylinder 154 is held in place by a series of support rods 158a-d in conjunction with the lower support plate 152 and an upper supportplate 160. A mounting plate 162 is attached to a rear portion of theupper support plate 160 at one end and to the lower support plate 152 atan opposite end. A support arm 164 is used to align the mounting plate162 in a vertical direction and is attached at one end to the mountingplate 162 and at an opposite end to the apparatus base 140.

[0086]FIGS. 27a-b, 28 a-b, and 29 a-b are schematic views of the plungerhead 142 apparatus with respect to the face, sole and crown components,respectively. As can be seen from the schematic drawings, the volume ofthe plunger head increases and decreases with respect to the particularcomponent to be manufactured. Preferable volume ranges for a plungerhead used in manufacturing a preform for a small face component mayrange from 10 in³ to 18 in³, with a more preferable volume of 14.4 in³.Alternatively, for a large face preform the preferable volume range forthe plunger head may be from 14.00 in³ to 18.00 in³, with a morepreferable volume of 16 in³. For a plunger head used in manufacturing apreform for the sole component a preferable volume range would be 25 in³to 32 in³, with a more preferable volume of 30.4 in³. Whereas for aplunger head used in manufacturing a preform for the crown component apreferable volume range would be 38 in³ to 45 in³, with a morepreferable volume of 41 in³. It should be understood that these are onlypreferable ranges and that depending upon the size and volume of theclub head desired the volumes of the plunger heads may be adjustedaccordingly.

[0087] From the foregoing it is believed that those skilled in thepertinent art will recognize the meritorious advancement of thisinvention and will readily understand that while the present inventionhas been described in association with a preferred embodiment thereof,and other embodiments illustrated in the accompanying drawings, numerouschanges, modifications and substitutions of equivalents may be madetherein without departing from the spirit and scope of this inventionwhich is intended to be unlimited by the foregoing except as may appearin the following appended claims. Therefore, the embodiments of theinvention in which an exclusive property or privilege is claimed aredefined in the following appended claims.

We claim as our invention:
 1. A method for forming preforms for a golfclub head, the preforms composed of plies of pre-preg sheets, the methodcomprising: placing a plurality of plies of pre-preg sheets in a moldcavity of a mold, the mold cavity configured to define a preform for acomponent of a golf club head; lowering a plunger head along alongitudinal axis toward the mold cavity, the plunger head configured tocompress the plurality of plies of pre-preg sheets into a component of agolf club head; compressing the plurality of plies of pre-preg sheetswith the plunger head to form a component of a golf club head; andremoving the component of a golf club head from the mold cavity.
 2. Amethod for forming a sole component for a golf club head, the solecomponent composed of plies of pre-preg sheets, the method comprising:placing a first plurality of plies of pre-preg sheets in a mold cavityof a mold, the mold cavity configured to define a sole component for agolf club head; lowering a first plunger head along a longitudinal axistoward the mold cavity, the first plunger head configured to compressthe first plurality of plies of pre-preg sheets into a sole componentfor a golf club head, the plunger head composed of an elastomericmaterial having a durometer of 25 Shore A to 85 Shore A; compressing thefirst plurality of plies of pre-preg sheets with the first plunger headto form a sole component for a golf club head; replacing the firstplunger head with a second plunger head, the second plunger head smallerin volume than the first plunger head; placing a second plurality ofplies of pre-preg sheets in the mold cavity over the first plurality ofplies of pre preg sheets; lowering the second plunger head along alongitudinal axis toward the mold cavity, the first plunger headconfigured to compress the second plurality of plies of pre-preg sheetsinto a sole component for a golf club head; compressing the secondplurality of plies of pre-preg sheets with the second plunger head toform a sole component for a golf club head; removing the sole componentof a golf club head from the mold cavity.
 3. A method for forming acrown component for a golf club head, the crown component composed ofplies of pre-preg sheets, the method comprising: placing a plurality ofplies of pre-preg sheets in a mold cavity, the mold cavity configured todefine a crown component for a golf club head; lowering a plunger headalong a longitudinal axis toward the mold cavity, the plunger headconfigured to compress the plurality of plies of pre-preg sheets into acrown component for a golf club head; compressing the plurality of pliesof pre-preg sheets with the plunger head to form a crown component for agolf club head; and removing the crown component for a golf club headfrom the mold cavity.